1. Field of the Invention
The invention comprises an apparatus and method for electronically determining distance and position on a surface.
2. Description of the Prior Art
The present invention arose from a need to conveniently determine the positions of the read and write heads of a small, hand-holdable microcopier, such as described in my copending application Ser. No. 06/338,505 filed Jan. 11, 1982. The portion of that application entitled "Description of the Prior Art" and the "Prior Art Statement" filed with that application contain a relatively complete description of the prior art relevant to said microcopiers. According to the disclosure of the invention in application Ser. No. 06/338,505, the position of the writing head and the position of the reading head relative to the surface of the paper were determined by markings on a wheel rolling on the surface of the paper. As the wheel rotated, the markings were detected and counted. The resulting count represented a measurement of the position of the microcopier over the surface of the paper. The present invention provides a way to reckon the position of the microcopier on the surface over which it is moved and involves no wheels or any body moving with respect to the microcopier.
The detection of heat on a surface is known in some areas of the prior art. See for example, the article entitled "Thin Linear Thermal Thermometer Arrays for Use in Localized Cancer Hyperthermia" by P. W. Barth and J. B. Angell, pages 144-150, Volume ED-29 #1, January 1982, IEEE Transactions on Electronic Devices. It is also believed that the following references may be relevant to the detecting of heat spots and the printing of information using thermal printing heads:
"New Type Thermal Printing Head Using Thin Film" S. Shibata, K. Murasugi & K. Kaminishi, pages 223-230 Volume PHP-12, #3, September, 1975, IEEE Transactions on Parts, Hybrids and Packaging; and;
"A Low Power Thermal Head Realizing High Quality Printing" by J. Yamazaki & M. Terashima, 1978 Components Conference Transactions, pages 264-270.
Insofar as can be determined, the invention appears to be novel in the context of the relevant prior art.